Circuit controller



Dec. 12, 1950 J. F. FRE'SE 2,533,233

CIRCUIT CONTROLLER Filed Aug. 31, 1945 4 Sheets-Sheet 1 Dec. 12, 1950 J. F. FRESE 2,533,238

CIRCUIT CONTROLLER Filed Aug. 51, 1945 -4 Sheets-Sheet 2 n I i I 6 gooey? 5" $4333,

Dec. 12, 1950 J. F. FRESE CIRCUIT CONTROLLER 4 Sheets-Sheet 3 Filed Aug. 31, 1945 Dec. 12, 1950 J. F. FRESE CIRCUIT CONTROLLER Filed Aug. 31, 1945 4 Sheets-Sheet 4 III. //A

Patented Dec. 12, 1950 UNIT ED "STATES PATENT:

OFFICE 15 Claims. 1 xMy invention relates broadly'to oil .switches and more particularly to animprovedconstruction ofmaintained contacttype of oil switch.

Onexof the objects of my invention is-: to'provide aconstruction of oilswitchin whichrmainwhich readily. replaceable plunger-like members and readilyreplaceable coacting contacts-are supportediin submerged. position in an oil bathz-and movement imparted to the plunger-like mem- .bersifor moving said members to eitherzof two limiting positions for establishing a maintained connection with the :coacting isubmerge'd .contacts.

istill another. object ot myinventiomis to:.pro- "v-i-de Jan -.improved1construction of .oil: switch :of

. the maintained: contact-types in which an::ang.u-

larlyishiftableeactuator :external to an .oil: filled casingsis arranged1to impart 'axialomovement: to sleeve members iOf insulation material acar'rying conductive bands operative: to= e'stablish bridging connectionwith coacting fixedmontacts nstill another object ofmy'zinvention is to.i:pro-

vide 'a sconstructi'on.of maintained contacttype of 'oil switch in which iamultiplicity of spaced contactmembers may he-"moved to either of L two limitingipositions with respect to coacting fixed contacts within an 0111113001, the movable -:and fixed contactseach being arranged for: readyreplacement or renewal.

:Stillanother object ofrmyinvention is toprovide a@ construction of *actuator for effecting alterna'te wiongitudinal displacement of .xmovable contact members with-respect tosspaced coacting fixed: contacts in which an angularly displaceable rackcoacts withia pair of annularly :grooved members :extending from the movable :con-tact members fo1-efiectingwa1ternate displacement thereof.

=ther' and .further "objects of i my invention reside in the novekconstruction: of replaceable fixedriand movable contacts :in .-a-n.oi1-.sw-itch of the-maintained contact type :as: set -forth" -more fully in the-specificationhereafter following by reference to the :accompanying drawings in which:

EigureiLisra front elevational view of theloil switch-:ofmyinvention; Fig. 2 is a rear elevational'viewJon1ine12-2 or Fig.5 showing theten minal connections for .the fixed 'contactors' of thexoil: switch;- Fig.--3 is a top; plan view showing themounting of the maintained type'of oilswitch on a terminal:.box,:and the actuator thereof; -Fig.:-4 is :a transverse: sectional view I taken sub.- stant-ially on line l. l ofrFigr 1;. Fig.=-5 is :a vertical sectional: view takensubstantially on line 55 of iFig. ;.1; Fig. :6:is a" fragmentary vertical sectional view through the :"switch actuating mechanism: taken-.-substantially= 'on' line 6-6 -:on Fig. -5 and illustrating .the limit. locking means for the .plunger members of the-oil switch; Fig. 7.:is' a vertical sectional View. on linev 'l-'! of: Fig. 5 illustratinguthev segmentallytoothed actuating memberz-whichsengages'with the;.grooves of the 'reciprocativeyplunger members for operating the switch Fig.'-8 isan elevational view of the bridging link whichsupports the switch locking mechanism; Fig. 9 is a transverse sectional View taken onlinex S-tof-Fig. '8;'Fig. 10 is a transverse sectional view taken substantially'on line Ill-40 of 'Fig: 6; Fig-11 is a plan view of the segmentally toothed actuator which engages the grooved heads on the :plunger members; Fig. 12 is a transversesectionalview takenon line |2-l2 of :Fig. 1l;..Fig. 13 is an elevational viewof the limitlockingmechanism for the plungermembers of the oil switch; Fig. 14 is a longitudinal sectional view takenon line |4--l4 of Fig. 13; Fig. 15 is a vertical sectional view showing a modifiediform of multiple contactor switch of the maintained contactor type embodying my invention; Fig. 16 vis a vertical sectional view taken substantially on line 16-16 of Fig. 15; Fig. 17 is a transversetsectional view taken substantially on line l1ll of Fig. 16; Fig. 18 a detail viewof enact the multiple contactors employedinthe' structureofsFigs; 15 and 16; Fig. 19 .i. diagrammatically .-illustrates the cooperative action ofthe roller :members of the rocker-with the camjfaces. of the locking latches of theswitch mechanismp-and Figs-20A, 20B, 20C, 20D, and 20E, illustrate-diagrammatically the Various arrangements of contacts of the maintained'typ'e which maybe employed in the oil switchrstructure of: .my I invention.

.Referring tothe drawings in" detail, reference character 1| designates a panel structure :ar-

ranged. to extend in asubstantially verticalxplane sand attachable through suita'b-le securing screWsZ with a terminal box represented at 3. The terminal box 3 is provided with suitable securing lugs 4 for attachment to a suitable supporting surface and is provided with a cable entrance represented at 5, through which cables may enter the terminal box leading to the oil switch. In Fig. 3 I have shown an alternative position for the cable entrance to the terminal box at 6. One of the important advantages of the oil switch construction of my invention resides in the fact that condensation, which might collect in the conduit leading to the terminal box 3 is obstructed from entering the oil switch contactor compartment illustrated generally at I.

The panel I has an integrally connected panel 8 which extends in a plane substantially normal to panel I. The panel 8 constitutes on its lower surface a cover for the oil container 9, while on its upper surface the panel member 8 has a housing l integrally connected therewith, said housing having the hollow interior thereof represented at H, opening into the terminal box 3 to permit the passage of cables into the oil switch contactor compartment 1. The housing Ill serves as an enclosure and protecting means for the movable actuators of the switch mechanism. An extension l2 formed on housing l0 serves as a hearing means for angularly shiftable shaft member 14. Shaft member l4 extends externally of the housing ,IO and has switch-actuating lever i5 secured thereto by suitable means, such as, transverse rivet member l6 which extends through lever l5 and shaft M to key the lever l5 to the shaft I4. The lever has oppositely directed pressure-applying pallets IT and I8 in-' tegrally connected therewith which may be alternately pressed manually for shifting the movable contactors within the compartment 1 from one condition to another condition.

The other end of shaft l4 extends interiorly of the housing l0 through the sealing washer lea into the hollow section II thereof and through the resilient spacer washer i3, and the latch supporting plate and between the locking latches 2| and..22 which are pivotally mounted thereon, to the rocker 23. Rocker 23 is keyed to the shaft H by suitable means, such as, transversely extending pin 24. The opposite ends of rocker 23 are se-g'mentally shaped and are provided with teeth represented at 26 and 21. The teeth 26 and 21 are engageable with the grooved heads 23 and 29 of the respective plunger members 30 and 3 I respectively.

The plunger members 30 and 3| each comprises single sections 30a and Ma connected to the sleeves of insulation material 43 and 44 respectively, by rivets 43a and 44a. The sections 33a and 31a. are slideable through the detachable screw-threaded bushings, or guide members 32 and 33.. The bushings 32 and 33 each have screw threaded portions 32a and 330. which enter screwthreaded openings 34 and 35 in the panel member 8 forming thetop of the contactor compartment 1. The screw-threaded bushings 32 and 33, and their associated plunger members 3!] and 3|, and grooved heads 28 and 29, constitute with the associated movable contact systems, assemblies which may readily be renewedor replaced from time to time as the movable contacts become worn. This is one of the outstanding advantages of the construction of my invention, in that the movable contact assembly may be renewed and replaced from time to time with or without the renewal of the co-acting fixed contacts-carried by the replaceable panel structure of insulation material represented generally at 36.

The bushings 32 and 33 are each provided with flanges 32b and 33b thereon which serve to clamp directly against the bridge member 31 for securing the bridge member 31' directly against the undersurface of panel B. The bridge memoer 31 has a central slot 38 therein, which is locked directly beneath the open slot 39 in the panel member 8, to receive the tongue 29a of the latch supporting plate 26. The latch supporting plate 20 and the locking latches 2| and 22 are supported in immediate relation to the rocker 23 by the keying action between tongue 23a and the slot 33 in bridge member 31. The locking latches 2| and 22 are pivoted On latch supporting plate 20 at 2|a, 22a but ofiset therefrom for distance suihcient to allow roller members 43 and 4|, which are carried by rocke 23 to be engaged by the cam faces 21b and 22b of the locking latches 2| and 22, as represented, for example, in Fig. 19. The locking latches 2i and 22 are normally biased to a position in which the latches are drawn together by coil spring 42. As the rocker 23 revolves by rotation of shaft i4 by pressure applied against actuating pallets i? or It, the roller members 40 and 4| operate against the cam portions 2l'b and 22b of locking latches 2| and 22, and maintain the actuator i5 to the position in which it is displaced, and for correspondingly maintaining the electrical contactors within the compartment 'l in the position in which the contactors are displaced, until positively moved to an opposite position by positive pressure exerted against either of the pallets l1 and is in the position illustrated in Figs. 20A-2OE. For example, roller 40 is latched above the cam portion 2| b of lever 2|, while roller 2| is latched below the cam portion 22b.of lever 22. In order to shift rocker 23 to .a reverse angular position, substantial pressure must be applied against pallet l8, thus avoid ing undesired operation of the switch by a slight, or unintentional pressure directed against the actuator pallet l8.

Each of the movable contact assemblies includes a sleeve member of insulation material which I have represented at 43 and 44, secured to the sections 3Ela-3|a of the plunger members 30 and 3| by suitable pins, as represented at 43a and 44a. The sleeves of insulation material 43 and 44 are each of such diameter that they will readily slide'within the shell-like portions 320 and 330 of the detachable screw-threaded bushings, or guide members 32 and 33. These sleeves of insulation material 43 and 44 serve as carriers for any variety of contact arrangements of the types represented in Figs. 20A, 20B, 20C, 20D, and 20E. In Figs. 1-6 I have represented a two-pole contactor of the type symbolically shown in Fig. 20E where one contactor is open and the other closed in which operation of the switch actuator results in the opening of one contactor and the closing of the other contactor according to the arrangement of Fig. 20E. As represented in Fig. 1, the sleeve of insulation material 43 carries the conductive band 45 in a position in which it is displaced from bridging relation between the sets of fixed contactors represented at 46 and 41, when the switch-actuated lever I5 is in the position illustrated in Fig. 1. At the same time, the conductive band 48, which is carried by sleeve of insulation material 44 is disposed in shunt or bridging relation between contactors 49 and 50, as shown. It will be observed that, as pressure is applied to pallet 18 of switch-actuating lever l5, con- "'5 --ductive bandi 48smovessout of bridging; relation .with the .coeacting .fixedcontacts 4e 1 and 59, while-conductive band 45 moves into bridging *relationwith coacting fixed contacts-. 36 and't'l, thus closing two electrical circuits. The fixed scontacts 4t,.-:4l;49 and- 55 consist of sprin members .vvhich extend from supporting terminal :strips 5|, 52, 53 and54, which are supported in .spacial relation on insulated panel structure 36.

Tonpreclude possibility of leakage between ter- -minal stripsbl and 52 of opposite potential, I .-,prov-ide projecting surfaceportions on the panel 36 intermediate the terminalstrips of opposite polarity. In Fig. 4 I'have shown the enlarged -opposite projectedsurface.portions 55'and 56 of insulated panel 36 projecting in opposite directions between the terminal strips 5i and 52. In -the case of terminal strips53 and 5d enlarged surface portions of panel 36, as represented at 51: and 58, project in opposite directions from the panel 36 between the terminal strips 53 and 54 of opposite polarity. Thus, very substantial insula- -tion'is.-provided between the terminals of op- .posite. polarity. Electrical connectionis made 'to theterminal strips 5|,152, 53 and 5 3 by means of. conductors anchored beneath the terminal screws :59, 60, Si, and'EZ. The panel of insulation materialtii is removably secured in a vertical plane to theundersurface of panel 8 by means of the removableand replaceable screw-threaded bolts 63-and 64. The removable and replaceable bolts Bit-and 54 pass through longitudinally extending apertures 65 and 66 in the enlarged surface portions 5556, and 515il of the panel 36, which are slotted at 56a and58a, respectively.

The-conductive bands 45 and 58 are each inclined at their opposite peripheral edges so that axial, or longitudinal movement of the plunger members and 3! have the effect of slightly spreading the co-acting fixed resilient contacts '46, 41, 49 and EiLpermitting substantial contact to be maintained between the respective conductive bands and the co-acting fixed contact. The-structure of the co-acting fixed contacts is shown more particularly in Fig. 5 as comprising --a substantially triangularly shaped bracket structure, such as is represented at 53, slotted at 5011 to impart resiliency to the contactor which is mounted on the terminal strip 54. The entire panel of insulation material 36, and the intermediate enlarged surface '55-5fi, and 5158 constitute a readily removable and replaceable unit which can be detached, or connected to the undersurface of the panel member 8, as indicated by the screw-threaded ends of the bolts 63, and 64 at 63a,-and 64d as they pass through the panel member 8. This permits the fixed contactor assembly-to be-renewed and replaced from time to time, as the fixed contacts become worn.

The entirecontact assembly, including both the movable and fixed contactors, are maintained in a pool of oil contained inthe tank or casing -9 which is-secured by means of screws 65 which pass through the panel member 8. The terminals "59, 6!}, Bi and 62 are all maintained above the level of the pool of oil,while the movable con tactors and it,.and the fixed co-acting contactors 45, Al, 49 andSD, are maintained below the level of the oil for quenching of the arcs which may occur therebetween. The cables vfrom terminal box 3 pass through housin ii, and :fIOIIlhOuSiIlg'l I through a cable entrance --in panel member .8 toestablish connection with :theterminal screws .59, bli s I and 52.

ta saases -As shown in-Figs. 15-18,:the. switch'systeni of my invention may bereadily applied to a double contactor system. In this arrangement, two panels of insulation material are. arranged symmetrically on opposite sides of the movable contact assemblies. I have represented one such insulated panel at 66, and the other insulated panel at 61. Panel 66 carries terminal strips 68, 69, 10, and H, to which there is secured the resilient contractors I2, 13, I4, and 15, which have conductive faces, shaped to establish engagement and electrical connection with the movable contactors. 'Provision is made for the insulation of the contactors of opposite polarity by the enlarged surfaces ofinsulation material represented at 16-41, and 18-19. The removable bolt members and 8| enable the panel of insulation material 66 to be readily removed and replaced.

Similarly, the panel of insulation materialzfil provides supporting means for terminal strips 82, 83, 84, and 85, to which resilient contactors 85, 87, 88, and 88 are connected. The plunger members 36, and 3!, carrying insulated sleeves 43, and

it are reciprocative between the co-acting sets of fixed contactors. In this arrangement the movable contactors comprise sleeve members 99 and Bi, and 92 and 93 separated by a disc member of insulation material represented atihl, and 35, respectively. This arrangement permits conductive sleeve 92 to be moved between stationary contactors 8t, and 81, while conductive sleeve3 is withdrawn from bridging relation between fixed contactors l2, and 73. Simultaneously, conductive sleeve 99 would be withdrawn from bridging relation with contactors 88 and 89, while conductive sleeve 98 would'be moved to conductive bridging relation with contactors M, and '15.

In the arrangement illustrated in Fig. 16, rocker 23 operates to shift plunger memberiwupwardly, and move plunger member 3! downward- 13' to afifect the circuit transfer above explained. The arrangement illustrated in Figs. 15-17 shows the relationship of movable and fixed contactors for a condition in which one set of contactors are maintained normally open, while another set of contactors are maintained normally closed, which is the condition illustrated in Fig. 28E.

Fig. 20A shows a condition in which a set of contactors, normally maintained in open circuit condition, may be conditioned to closed circuit condition upon movement of the maintained type of plunger member.

Fig. 203 illustrates-the condition where a set of contactors are normally maintained closed, and are opened by movement of the plunger members.

Fig. 20C illustrates a construction of switch in which two sets of contacts are normally maintained closed, but are opened by displacement of the movable contact assembly.

Fig. 20D illustrates a condition in which two sets of contacts are normally maintained open, but are bridged by displacement of removable contact assemblies.

Fig. 20E, as aforesaid, illustrates a condition which is composite in character with respect to the arrangement of Figs. 20C, and 20D, that ls, wherein one set of contacts are maintained closed, while the other set of contacts are maintained open, and wherein the reversed condition may be efiected by displacement of the plunger member.

The grooved heads 28 and 29, which'engage with the teeth 26 and 2! in the opposite ends of 76 rocker 23, are freeto turn withinthe gear teeth 26 and 21 without advancing in'their longitudinal position, whereby the conductive bands 45 and 48 are slowly rotatively moved. Thus, a fresh conductive surface is presented to the stationary contactors progressively, thereby extending the life of t e contact system. The fact that the parallel grooves on grooved heads 28 and 29 may be axially revolved while remaining in engagement with the gear teeth 26 and 2i on rocker 23 enables a maintenance adjustment to be made of each of the plunger members 30 and 3! in order to present a fresh surface contact between the movable contact assemblies and the fixed contacts. This axial adjustment may be made throughout the entire angular distance of 360 in a plane transverse to the movable and fixed contact assemblies in either the projected or retracted positions of the plunger members. The fact that the guide members 32 and 33 have shelllike portions 320 and 330 surrounding the sleeves of insulation material 43 and 44 insures the precision axial movement of the plunger members 30 and 3! and the accurate registration of the movable contacts with the stationary contacts.

The fact that the parts of the switch of my invention may be readily removed, replaced and installed makes it possible for a customer or user to purchase the elemental parts of the switch and make the installation in the field in accordance with the requirements of a particular problem. I realize that other contact arrangements may be provided in the maintained type of oil switch illustrated herein, and I desire that it be understood that such modifications are to be included within the scope of my invention and that no limitations upon my invention are intended other than may be imposed by the appended claims.

What I claim and desire to secure by Letters Patent of the United States is as follows:

1. Control mechanism for a switch comprising a housing, a set of fixed contactors insulatingly and removably supported by said housing on substantially spaced parallel axes, a pair of movable contact assemblies replaceably supported in said housing adjacent said fixed contactors, said movable contact assemblies each including a reciprocative plunger member, an insulation member connected therewith, a contact supported by said insulation member, a head connected with each of said plunger members, annular grooves formed On each of said heads and a rocker mounted for pivotal movement between the heads of said plunger members, said rocker having peripheral teeth on the opposite ends thereof engageable with the annular grooves in said heads for selectively and alternately linearly shifting said plunger members to positions in which the contact carried by said insulation members may be selectively connected with or disconnected from said co-acting fixed contactors the annular grooves of said heads being unrestrictedl revolvable within the teeth of said rocker.

2/ Control mechanism for an electrical switch comprisi housing, a pair or replaceable movable contact assemblies supported on substantially spaced parallel axes by said housing, a plunger member individual to each of said movable contact assemblies and extending through said housing, a cylindrical head on each of said plunger members provided with a multiplicity of parallel spaced annular grooves, a rocker pivotally mounted externally of said housing in a position intermediate said cylindrical heads, said rocker havin segmentally arranged. teeth on each end thereof engageable with the spaced an nular grooves in each of said cylindrical heads, means external to said housing'connected with said rocker for shifting said rocker to either of two limiting positions and imparting longitudinal movement to each of said plungers without restricting the revolvability of said movable contact assemblies, contacts carried by each of said movable contact assemblies, and co-acting fixed contactors carried by said housing, said contacts and fixed contactors being connected, or disconnected according to the linear movement of said plunger members.

3. Control mechanism for an electrical switch comprising a housing, a pair of replaceable movable contact assemblies, supported by said housing on spaced substantially parallel axes, a plunger member individual to each of said movable contact assemblies and extending through said housing, a cylindrical head on each of said plunger members provided with a multiplicity of spaced annular grooves, a rocker pivotally mounted in a position intermediate said cylindrical heads, said rocker having segmentally arranged teeth on each end thereof engageable with the spaced annular grooves in each of said cylindrical heads, means for shifting said rocker to ither of two limiting positions and imparting longitudinal movement to each of said plungers without restricting the revolvability of said movable contact assemblies, contacts carried by each of said movable contact assemblies, co-acting fixed contactors carried by said housing, said contacts and fixed contactors being connected, or disconnected according to the movement of said plunger members, and means for latching said plunger members at either limit of the respective linear movement thereof.

l. Control mechanism for an electrical switch comprising a housing, a pair of replaceable movable contact assemblies supported by said housing on spaced substantially parallel axes, a movable and revolvable plunger member individual to each of said movable contact assemblies and extending through said housing, a cylindrical head on each of said plunger members provided with a multiplicity of spaced annular grooves, a. rocker pivotally mounted in a position intermediate said cylindrical heads, said rocker having segmentally arranged teeth on each end thereof engageable with the spaced annular grooves in each of said cylindrical heads, means for shifting said rocker to either of two limiting positions and imparting longitudinal movement to each of said plungers without restricting the revolvability of said movable contact assemblies, contacts carried by each of said movable contact assemblies, co-acting fixed contactors carried by said housing, said contacts and fixed contactors being connected, or disconnected according to the movement of said plunger members, and a pair of yieldably latching levers associated with said rocker for locking said plunger members in either of the limits of the paths of movement thereof.

5. Control mechanism for a switch comprising a housing, sets of fixed contactors removably supported on substantially spaced parallel axes on said housing, a pair of parallel spaced movable contact assemblies replaceably supported by said housing adjacent said fixed contactors, said movable contactor assemblies including linearly reciprocative plunger members each having an annular grooved longitudinally extending portion on one end, and an insulated portion on the other end, a contact carried by each of the insulated agbssgasz-idisconnected from the co"-actingfixed contactors,

a rocker' disposed intermediate the annulargrooved longitudinally extending portions of 'said I plunger members, teeth formed-on each end of said rocker andengageable with theannulargroovedlongitudinally extending portions of said plunger members for imparting motionto-said plunger members in; opposite directions as said rocker is angularly shift'edwithout restricting therevolvability of said movable contactessembliss, and amanually controllable actuator'for imparting angular movement to said rocker.

6. Controlmechanism" foranelectric switch" including a housing, a pair-of movablecontact assemblies disposed on substantially parallel-axes and replaceably supported by said housing; each' of said movable contact assemblies including aninsulated portion, sleeve-like contactscarried-by the said insulatedportions at'spaced intervalsthereon, a disc ofinsulation-material disposed bc tween said sleeve-like contacts, ,sets of (to-acting fixed contacts disposedon substantiallygparallelan angular distance of 360, with'saididiscs of in sulation material interposedrbetweezrtsaid sleevelike contacts and said fixed contactors.

7. Control mechanism for anelectric switch in cluding a housing structure; a pair ofreciprocative' plungermembers having movable, con.- tactassemblies mounted thereon;and coasting with sets of fixed contactors carrieduby saidhouse ing structure; an" elongated: cyiindrical head; on each of said 'plunger'members, symmetrically dis posed spaced flanges formed on each of said elon gated cylindrical heads, a control shaft journaled in said housin structure in a position intermediate said elongated cylindrical heads, and a rocker plate carried by said control shaft and extending between said pair of reciprocative plunger members coplanar with the axes thereof, said rocker plate having segmental teeth on each end thereof, the segmental teeth in diagonally opposite portions of said rocker plate meshing with the spaced flanges at diagonally opposite ends of the spaced elongated cylindrical heads on said plunger members for projecting and retracting said reciprocative plunger members said members being individually angularly adjustable through 360 while being alternately projectable and retractible through said housing structure for controlling the connection and disconnection of movable contact assemblies and said coactsets of fixed contacts.

8. Control mechanism for an electric switch including a housing structure, a pair of reciprocative plunger members having movable contact assemblies mounted thereon and coacting with sets of fixed contactors carried by said housing structure, an elongated cylindrical head on each of said plunger members, symmetrically disposed spaced flanges formed on each of said elongated cylindrical heads, a control shaft journaled in said housing structure in a position intermediate said elongated cylindrical heads, a rocker plate carried by said control shaft and extending between said pair of reciprocative plunger members l (.1 coplanarwith theaxes thereof," said-rocker plate having segmental teeth on each end thereof meshingwith the" spaced flanges formed" on each of said elongated cylindrical heads the fiangeson' said heads being individually angularly adjustable through 360" whilebeing alternately projectable and retractiblethrough said housing structure, the segmental teeth indiagonally opposite por tions of said rocker plate meshingwith'fianges at diagonally opposite ends "of the spacedielongated' cylindrical heads on said plunger members for controlling the connection and disconnection of said movablecontactiassemblies 'and'said coacting sets of fixed'icontacts; and latching mecha'- nism' mounted on said'. housing structure for" maintaining said plunger members in either of the projected orretracted positions thereof:

9. Control, mechanism for'ani electric switch including a, supporting structure and a." pair of electrical contact members reciprocative: therethrough, a rocker arm pivotally mounted on'said supporting structure'and operativel connected with said pair of' electrica-lcontact members; a pairlof spaced'cam'devices carried by saidrockei" arm, a plate membenmounted on said support lug structure; a pair of*latching levers pivota'lly mountedon said plate member, inwardly directed detents on. said 'levers disposed-in the "path of the cam members'on said? rockerarm, an'dspring' meansfor yieldably drawing said *lever' members together and inengagement 'witlrsaid cam meanbers, for yieldably maintaining the detents on'said" lever members on eitherside'of saidcammem bers on said rocker arm :for' yieldably'retaining' the rocker arm in'eith'er of two'opposite-limiting" positions thereof for maintaining the selected position of said electrical contact"members:

10. A' contactassembly for electric switches" comprising in combination witha'housingi'a' pair w of alternately reciprocative contact assemblies replaceably supportedb'y the housing; abridge member extending 'b'etweerr'an'd positively spac ing said contacvassemblies, a plate member sup-'- ported by said bridge member in a plane normal thereto and in a position spaced from said con tact assemblies, a pair of latching levers pivotally mounted on said plate member, detents carried by the inner faces of said latching levers and directed toward each other, a rocker for controlling the alternately reciprocative movement of said contact assemblies and operative between said reciprocative contact assemblies in a plane parallel to but spaced from the plane of said plate member, cams carried by said rocker and pro jecting into the plane of the detents on said levers, and means urging said cams into yieldable engagement with the detents on said levers for yieldably latching said rocked in either of the limits of angular movement thereof.

11. A contact assembly for electric switches in cluding a supporting structure, a sleeve member detachably mounted on the supporting structure and including a guide shell extending therefrom, a plunger member mounted for sliding movement through said sleeve member and axially throng; said guide shell in annular spaced relation thereto, a sleeve member of insulation material carried by said plunger member and slidable in said guide shell and terminating within said guide shell in spaced relation to the interior end thereof to permit sliding movement of said sleeve of insulation material under control of said plunger member, an electrical contact carried by said sleeve of insulation material and a fixed elec trica co act carried by said supporting struc- 11 ture in the path of movement of the aforesaid electrical contact. r

12. A contact assembly for electric switches including a supporting structure, a cylindrical shell open at one end thereof and detachably mounted at the other end on said supporting structure, a plunger member axially slidable through said cylindrical shell in spaced relation to the interior walls of said cylindrical shell, a sleeve of insulation material connected with the end of said plunger member and terminating short of the internal end of said cylindrical shell, said sleeve of insulation material conforming to the interior diameter of said shell and being slidable therein under control of said plunger member, a movable electrical contact carried by said sleeve of insulation material and a stationary contact mounted in insulated relation to said supporting member in alignment with the movsaid cylindrical shell guide, a sleeve of insulation material carried by the end of said plunger member in a position conforming with the interior I diameter of said cylindrical shell guide and terminating short of the internal end of said cylindrical shell guide, a movable electrical contact carried by said sleeve of insulation material and operative to establish a connection and disconnection with respect to said fixed contact as said plunger member moves axially through said cylindrical shell guide.

14. Control mechanism for an electric switch actuator comprising a supporting structure, a removable sleeve mounted on said structure, a plunger member axially slidable through said sleeve, a contact assembly in supporting relation to one end of said plunger member and an operating head carried by the other end of said plunger member, said operating head including a plurality of spaced parallel extending flanges operative to be engaged at a multiplicity of linearly spaced positions along the length thereof for imparting a sliding movement to said plunger member for displacing the plunger member with respect to said cylindrical shell guide.

15. In a switch actuator, an angularly revolvable control shaft, a rocker arm mounted on the control shaft, and having a cam member extending longitudinally from the face thereof on each side of said control shaft, a plate member supported in parallel spaced relation to the plane of said rocker arm, a pair of pivotally mounted levers carried by said plate member on the side thereof adjacent the cam members on said rocker arm, detents carried by said lever members and operative to engage on either side of the cam members carried by said rocker arm and plunger members for yieldablly drawing said lever members together for maintaining the detents thereon in the path of movement of said cam members whereby angular movement of said shaft may be arrested and maintained in either of two limiting positions thereof.

JOSEPH F. FRESE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Edmonds May 26, 

